The present invention relates to microwave filters and more particularly to a superconducting stripline filter structure for reducing electromagnetic leakage.
There are many applications for high Q, low loss filters including, for example, radar systems. Some radar systems employ filter banks operating in frequencies ranging from the S band to the Ku band. These filters typically have passband widths in the range of 50-100 MHz. In radar systems, the filters are required to have low insertion loss, high dynamic range, and a small size. To achieve the narrow passband widths, the filters need unloaded Qs in the range of 10.sup.4. Typically, with current superconductor technology stripline microwave filters can have high Qs and small sizes. However, mechanical connections to stripline filters normally require the use of microstrip structures. Such microstrip structures cause the generation of spurious waveguide modes within the filter due to its asymmetrical structure.